Display of the web page is performed by a web browser. At this time, the web browser acquires an HTML document (an HTML file) from a web server, parses the HTML document to generate a Document Object Model (DOM) tree, generates various rendered elements based on the DOM tree and displays the web page (for example, refer to PTL 1).
The Document Object Model (DOM) is present in the World Wide Web Consortium (W3C) standards. The DOM defines a tree structure in which the outermost tag, <html>, is the top node in relation to one HTML document, and designates an interface for applying dynamic processing by JavaScript to each parameter of tags. Note that “JavaScript” is a registered trademark.
In recent years, a method defined in MPEG Media Transport (MMT) ISO/IEC 23008-1 is attracting attention as a transport method suitable for next generation broadcasting. MMT not only defines the transport layer, but also a data structure referred to as MMT Composition Information (MMT-CI) which describes the configuration of the screen or a change with time. The MMT-CI configures presentation control information of transport media such as video, audio, and images. The MMT-CI is defined by HTML 5.